1. Field of the Invention
The invention relates to manufacturing equipment and, more particularly, to a transporting apparatus for vehicle assembly plants which extend, for example, along production lines.
2. Description of the Related Art
Assembly lines have been used for a long time (i.e., decades) in vehicle assembly plants to optimize manufacturing runs. Vehicles to be manufactured, i.e., motor cars, are transported from one workstation to the next. At each workstation, usually only a few, relatively simple working steps are performed. Conveying systems used for transporting vehicles in vehicle assembly plants must meet a large number of requirements. Firstly, the vehicles to be transported are relatively heavy as workpieces. Secondly, the vehicles have to be readily accessible to be worked on from as many sides as possible, i.e., for performing working steps ergonomically.
Usually, vehicles that are not completely assembled are transported in a vehicle assembly plant by overhead conveyors. Electric overhead conveyors are known and in wide use. DE 31 46 807 A1 discloses one such conveying system in which a motor vehicle body is suspended on supports for transport. Work, such as installing wiring or fixtures in the engine compartment, frequently occurs when the motor vehicle body is being transported by an overhead conveyor. In many cases, after a vehicle has been worked on as a suspended workpiece, the vehicle to be assembled must be transferred to a platform system on which the vehicle is transported. This usually occurs before or after the drive train and the vehicle body have been joined together as part of a “wedding”. When the vehicle to be assembled is transported on the platform system, the vehicle is readily accessible for work, such as the adhesive bonding of glazing, or the installation of doors, cockpit or seats.
DE 10 2005 062 691 A1 describes another conveying system in an assembly plant for motor vehicles, where a moveable platform which comprises a lifting apparatus for a motor vehicle is provided for each motor vehicle. Here, the lifting apparatus is arranged in a vertical projection next to the motor vehicle. A moveable platform is provided for essentially any motor vehicle to be manufactured. The motor vehicle remains on the platform throughout the manufacturing sequence. As a result, complicated transferring of the motor vehicle from an overhead conveyor onto a platform system can be eliminated, thereby providing a manufacturing sequence that is less susceptible to interruptions.